ES2815529T3 - Rotating peristaltic pump without pulses - Google Patents

Abstract

An infusion pump device, comprising peristaltic pump means including - a flexible, preferably elastic, stationary tube (36) having an inlet (50) and an outlet (52) and is provided to accommodate a flowing fluid downstream from the inlet (50) to the outlet (52), and - at least two engaging elements (22, 26) which are spaced from each other by a constant predetermined distance and which are provided to engage locally with the tube (36) and to be repeatedly moved along the tube (36), in a downstream direction, to locally squeeze the tube (36) and achieve a pumping action during the movement of the latch along the tube ( 36) and to encapsulate a volume of the tube (36) between two adjoining hooking elements (22, 26), - wherein the tube (36) comprises first to fourth zones (A to D) that are directly joined to each other in downstream direction, - where the first zone (A), which is the most upstream zone, it is provided so that a hooking element (22, 26) can engage with the tube (36) during movement along the first zone (A), - where the second and third Zones (B, C) are provided so that an engagement element (22, 26) remains engaged with the tube (36) during movement along the second and third zones (B, C), - wherein the fourth zone (D), which is the most downstream zone, is provided so that a hooking element (22, 26) can be disengaged from the tube (36) during movement along the fourth zone (D), - where the length of each of the first, second and fourth zones (A, B and D) is shorter than the distance between the two adjoining hooking elements (22, 26), and - where the cross section of the second zone (B) is greater than the cross section of the third zone (C) by an amount that leads to a volume increase that is at least equal to a volume increase after positioned in the fourth zone (D), as a result of unhooking a hooking element (22, 26) from the tube (36), characterized in that - the second zone (B), which follows the first zone (A) in the direction downstream, it begins at a starting point where a latch (22) enters the second zone at the same time as an adjoining front latch (26) located in the fourth zone (D) simply stops tightening the tube ( 36), and it will be unhooked from the tube (36) so that a flow communication arises, - the third zone (C), which follows the second zone (B) in a downstream direction, begins at a starting point where a coupling element (22) enters the third zone (C) at the same time that a front coupling element (26) adjoining the tube (36) has already been disengaged and, therefore, no longer makes contact with the tube (36), - the length of the third zone (C) is also shorter than the distance between the two connecting elements (22, 26) adjoining before, - the sum of the distances of the second and third zones (B, C) is equal to the distance between the two neighboring coupling elements (22, 26), and - the length of the second zone (B) is equal to the length of the fourth zone (D).

Description

DESCRIPTION

Rotating peristaltic pump without pulses

Field of the invention

The present invention relates to an infusion pump device comprising peristaltic pump means that includes a stationary, preferably elastic, flexible tube having an inlet and an outlet and is provided to accommodate a fluid flowing downstream from the inlet to the outlet, and at least two latch elements that are separated from each other by a predetermined constant distance and arranged to engage locally with the tube, and to be repeatedly moved along the tube in a downstream direction, to locally tighten the tube in order to achieve a pumping action during movement along the tube and encapsulate a volume of the tube between the adjoining latch elements.

Background of the invention

Syringe pumps are used in medical practice for drugs that require high precision and have a short half-life once in the body. In operating rooms and intensive care units, syringe pumps are mounted in stacks of pumps, particularly six to eight, which, however, require a lot of space and only allow low visibility and recognition of the indication of the drug provided. in the syringe. Apart from the fact that they occupy large spaces, syringe pumps present more problems, since in practice a nominal horn curve cannot be achieved, and therefore also a constancy index, because the plunger (normally manufactured with rubber) sticks to the walls of the syringe and therefore advances in pulses rather than continuously. Additionally, syringe pumps also have low sensitivity to occlusion pressure reading, which is a problem for neonatal infusions and, recently, for the use of large volume portable bolus injectors. Syringe pumps are widely used mainly in Europe, where approximately 40% of all hospital beds are equipped with a syringe pump, and are used in insulin infusions and most immunoglobulin infusions and for Parkinson's disease. It has been proposed to replace insulin syringe pumps with diaphragm pumps, which, however, cannot be implemented as insulin crystallizes and causes the active and passive valves of the mechanism to leak.

Pre-filled syringes are part of a growing sector of pharmaceutical administration and work well for injections, but are problematic for long-term infusions as they become bulky, especially for newer biologics, and have a maximum volume approximately 60 to 100 ml. Thus, the pumps become bulky as the required infusion volume increases.

Syringe pumps are used because prior art peristaltic pumps had low precision and caused pulsatile flow and thus non-linear flow per infusion cycle, where during part of the cycle no infusion occurs but at Reflux is sometimes generated, so its constancy index is high for drugs with a short half-life. Short-term precision can be expressed by the concept of a constancy index. This is the shortest period during steady state operation of a pump during which an output measurement consistently falls within / - 10% of the mean rate. These data are derived from flow tests performed for 24 hours at 1 ml / h, where the flow is recorded at 30 second intervals during the final 18 hour period and during each short period the average rate is compared with the flow.

Peristaltic pumps comprise a casing and a compressible tube arranged within the casing. There are basically two different embodiments of the peristaltic pump, where in one embodiment the tube is arranged along a straight track, while in the other embodiment the tube is formed as a loop resulting in a more economical design, with smaller physical size and lower production costs. The first embodiment, which is called a linear peristaltic pump, is the one that is mainly used today, while the present invention relates to the latter embodiment. The tube must be filled with a fluid to be supplied from its inlet to its outlet. Movement of the fluid through the tube is caused by latching elements, usually in the form of rollers driven by rotary means such as an electric motor or a mechanically driven shaft. The latches cause an occlusion of the tube by pressing it against a wall or track located within the housing, so that fluid is forced through the tube due to the movement of the latches. The use of a peristaltic pump is advantageous insofar as the fluid does not come into contact with the operating environment, making the peristaltic pump suitable for medical applications such as drug infusion when it is important to avoid fluid contact with the environment. Additionally, the mechanical components of a peristaltic pump do not come into contact with the fluid. Thus, the components of a peristaltic pump remain free from contamination by the fluid. As a result, a peristaltic pump is easy to clean and sterilize because the tube can simply be discarded after use, and because a new tube can be provided for the next use.

However, a disadvantage is that with a peristaltic pump it is difficult to achieve a constant or pulseless flow of fluid through the tube. Disengaging the engaging elements from the tube creates pulses and thus the occlusion is removed with the result that a vacuum is generated in the tube disengagement area. Namely, in this area the tube returns to its normal round shape, which results in an increase in the volume that is filled with fluid from the tube outlet. This leads to a reduction in the flow rate of the fluid at the outlet of the tube during the duration of the pulse.

In other words, the pulsatile behavior of a rotating peristaltic pump results from the alternation between a leading or leading engagement element and the next following or subsequent engagement element. V is the volume that is encapsulated between two adjoining coupling elements. In the case of a rotating peristaltic pump, defining 9 an angular position so that the angular position of the rear coupling element is 9 I and the angular position of the front coupling element is 92, the volume V encapsulated between both mentioned coupling elements extends over an angular distance that is defined by the difference between the two angular positions 92 and 9 I mentioned above, that is, A9 = 92 - 91. AV / A9 represents an increase in volume that defines a so-called frontal wave that is displaced in front of each coupling element, which makes it advance. -AVZ A9 represents a decrease in volume that defines a so-called depression, which arises behind each coupling element. The enclosed volume V between two adjoining coupling elements that clamp the tube with an unaltered distance between them is constant, so that the fluid is simply transported if AV / A9 and -AV / A9 are equal, so that

V AV / A9 - AV / A9 = V,

which results in that also the pressure remains constant.

If, otherwise, an upstream portion of the tube is larger than a downstream portion, so that AV2 / A9> AV1 / A9 and

V AV2 / A9 - AV1 / A9 = V Vdifference,

where AV1 / A9 represents an increase in volume defining a front wave in front of the leading or leading latch and AV2 / A9 represents an increase in volume defining a front wave in front of the next follower or rear latch, pressure increases due to the forces of the elastic tubes of the inflated portion due to the increase in volume.

The moment the front latch stops squeezing the tube and front / rear communication is established through a thin film of fluid below the tube, the AV / A9 front wave suddenly disappears (so that it can no longer push fluid) and is replaced by the front wave in front of the rear latch, which now takes over from the infusion. Also, -AV / A9 disappears behind it. But due to the disengagement of the front hitch, a new additional difference volume AVd / A9 accumulates and continues to be present until the disengagement of the front hitch is completed. A vacuum is generated which creates the aforementioned new additional volume difference AVd, if the flex tube becomes asymptotic or starts with a larger diameter release bend at this point, resulting in the creation of a negative AV / pulse A9 - AVd / A9 in the flow chart (V, 9) (where AVd depends on the geometry of the latch element and the Ar / A9 release curvature of the casing, and r is the radius of the release bend that increases for allow the latch to disengage).

The flow is defined as AV / At. By multiplying each of the nominator and denominator with A $, the above equation can be written as

flow = (AV / A9) • (A9 / At).

This makes it clear that for a constant rotational motion A9 / At, if AV is constant in the vicinity of a latch at any location along its path of motion, the flow rate will be constant without any variation or impulse.

The lack of constant fluid caused by pulsing in the tube makes a peristaltic pump unsuitable for certain precision applications. For example, in applications where a small volume of fluid is required, such as when less than one full revolution of the rotor is used, the effect of pulses is particularly disadvantageous.

Document US 5533 878 A discloses a compression type pump where the elastic tube has a larger diameter at the beginning of an infusion cycle than at the end.

Document US 7654 127 B2 discloses a peristaltic pump with dimensions increased in a portion upstream of the tube, to increase the pressure within the tube before disengaging a roller that squeezes the tube. However, when the front roller is about to be disengaged from the tube, the pressure is suddenly released. Therefore, a flow disturbance occurs first with a sudden increase in flow and then with a decrease in flow by the same amount due to disengagement of the roller from the tube after a few degrees of rotation.

Document US 3826593 A proposes the provision of a cam that compresses the tube at another point at the same time that the engagement roller is disengaged from the tube, in a peristaltic pump. However, this solution requires higher costs and a greater number of mounting parts and is therefore not suitable for a disposable pump mechanism.

Document US 5470211 A deals with a roller pump with the provision of a controlled curvature at the inlet and outlet of the tube.

US 2006/0245964 A1 discloses a rotary peristaltic pump comprising a pump casing, a compressible pump tube positioned between rotary occlusion members and a pump tube track in the casing, where in the tube track An opening is present between a first occlusion member and a second occlusion member so that when the second occlusion member has ceased to occlude the pump tube in the opening, a third occlusion member completes the occlusion of the pump. pump tube and thus capture a fluid compensation volume between the first and third occlusion members, and when the second occlusion member again produces an occluding action at the end of the opening, move the compensation volume toward the outlet of the pump tube, thus maintaining the velocity of the fluid in the outlet stream.

An object of the present invention is to provide a continuous duty, pulseless, precise peristaltic pump that is small in size so that it can replace many of the bulky syringe pumps in a limited space.

Summary of the invention

To achieve the above object and further objects, in accordance with the present invention, there is provided an infusion pump device comprising peristaltic pump means, including

- a flexible stationary tube, preferably elastic, having an inlet and an outlet and is provided to accommodate a fluid flowing in a downstream direction from the inlet to the outlet, and

- at least two engaging elements which are spaced from each other by a constant predetermined distance and which are provided to engage locally with the tube and to be repeatedly displaced along the same, in a downstream direction, to locally tighten the tube and to achieve a pumping action during movement of the latch along the tube and to encapsulate a volume of the tube between two adjoining latches,

- wherein the tube comprises a first to fourth zones that are directly connected to each other in a downstream direction,

- wherein the first zone, which is the most upstream zone, is provided so that a latch element can engage with the tube during movement along the first zone,

- wherein the second and third zones are provided so that a latch element remains engaged with the tube during movement along the second and third zones,

- wherein the fourth zone, which is the most downstream zone, is provided so that a hooking element can be disengaged from the tube during movement along the fourth zone,

- where the length of each of the first, second and fourth zones is shorter than the distance between the two adjoining hooking elements, and

- wherein the cross section of the second zone is greater than the cross section of the third zone by an amount that entails an increase in volume that is at least equal to an increase in volume displaced in the fourth zone, as a result of disengagement from the tube a coupling element,

characterized by what

- the second zone, which follows the first zone in a downstream direction, begins at a starting point where a coupling element enters the second zone at the same time as an adjoining front coupling element located in the fourth zone simply stops squeeze the tube, and it will unhook it from the tube so that a flow communication arises,

- the third zone, which follows the second zone in a downstream direction, begins at a starting point where a coupling element enters the third zone at the same time that an adjoining front coupling element has already been disengaged and therefore Therefore, it no longer makes contact with the tube,

- the length of the third zone is also shorter than the distance between the two neighboring coupling elements,

- the sum of the lengths of the second and third zones is equal to the distance between the two elements of adjoining hitch, and

- the length of the second zone is equal to the length of the fourth zone.

Preferred embodiments and modifications are defined in the dependent claims.

Preferably, the length of the third zone is greater than the length of the first zone and / or the second zone and / or the fourth zone.

Preferably, the cross section of the first zone is larger than the cross section of the third zone, in particular in a case where the downstream operating pressure is relatively high.

Preferably, a housing is provided which houses the peristaltic pump means, and a fixing means for fixing the tube to the housing to prevent movement of the tube with respect to it, resulting in greater precision in order to improve the repeatability of the process. According to a modification of the present embodiment, the fixing means can be provided as anchors and / or adapted to be able to fix the tube to an inner wall of the housing.

According to a further preferred embodiment, the peristaltic pump means is a rotary peristaltic pump means comprising a rotor that is provided with the hooking elements, wherein the tube comprises a bent portion that has essentially a partial cycle shape, where the length of the zones is represented by an angular distance.

According to a preferred modification of the aforementioned embodiment, the angular distance of the first zone is up to 15 °.

According to a preferred modification of the aforementioned embodiment, the angular distance of the second zone is from 20 ° to 60 °.

According to another preferred modification of the aforementioned embodiment, there are two hooking elements that are arranged essentially diametrically opposite to an axis of rotation of the rotor, where the sum of the angular distances of the second and third zones is equal to 180 °

According to an alternative modification, there are three engagement elements that are separated from a rotational axis of the rotor by the same radial distance, wherein two adjoining engagement elements are separated from each other by an angular distance of 120 °, where the sum of the angular distances of the second and third zone is equal to 120 °.

According to another preferred modification of the aforementioned embodiment, the latch elements are provided as latch rollers.

According to a preferred modification, the rotor comprises a central roller that is frictionally engaged with the engagement rollers.

According to another preferred modification of the aforementioned embodiment, there are provided

- a housing that is divided into at least three operating layers placed one on top of the other, wherein - an epicyclic gear layer includes an epicyclic gear means comprising a rotating center gear, a stationary outer ring gear surrounding the center gear and movable planetary gears, which are arranged between the center gear and the ring gear and in movable engagement with the center gear and the ring gear,

- a bearing layer includes a roller bearing means, comprising a stationary outer ring and an arrangement of movable inner rollers that are movable with respect to the outer ring and are engaged with the epicyclic gear means, to provide a rotating bearing for center and planetary gears, and

- A pump operating layer includes the rotary peristaltic pump means wherein the rotor is engaged with the center gear of the epicyclic gear means so that a torque is transferred from the center gear to the rotor.

According to a preferred modification, the rotor is non-rotatably coupled in a coaxial arrangement with the center gear of the epicyclic gear means.

According to another preferred modification, the inner roller arrangement of the roller bearing means is non-rotatably engaged with at least the center gear of the epicyclic gear means.

According to another preferred modification, the inner roller arrangement of the roller bearing means comprises a rotating central roller and movable planetary rollers which are arranged between the central roller and the outer ring, and in mobile friction coupling with both the central roller and the outer ring.

According to another preferred modification, the center gear of the epicyclic gear means is non-rotatably engaged in a coaxial arrangement with the center roller of the roller bearing means.

According to another preferred modification, at least one of the planet gears of the epicyclic gear means is non-rotatably coupled in coaxial arrangement with one of the planetary rollers of the roller bearing means.

According to another preferred modification, the roller bearing means comprises two planetary rollers which are arranged essentially diametrically opposite to the axis of rotation of the central roller.

According to another preferred modification, the epicyclic gear means comprises two planet gears which are arranged essentially diametrically opposite to the axis of rotation of the central gear. According to another preferred modification, at least one of the engagement rollers is non-rotatably engaged in a coaxial arrangement with one of the planet gears of the epicyclic gear means. According to a preferred modification, the rotor of the rotary peristaltic pump means comprises a central roller which is in frictional engagement with the engagement rollers and is non-rotationally engaged, in a coaxial arrangement, with the central gear of the gear means epicyclic.

According to a preferred modification, the gear ratio between the planetary gears and the center gear of the epicyclic gear means corresponds to the ratio between the diameter of the engagement rollers and the diameter of the center roll of the rotor of the rotary peristaltic pump means. .

Preferably, the center gear of the epicyclic gear means, the center roll of the roller bearing means, and the center roll of the rotor of the rotary peristaltic pump means are commonly formed as an integral central rotary body, and / or wherein at least one Planetary gear of the epicyclic gear medium, a planetary roller of the roller bearing medium and a rotor engagement roller of the rotary peristaltic pump medium are commonly formed as an integral rotary planetary body.

According to a further preferred embodiment, the casing includes a bent wall portion supporting at least a portion of the tube and giving it a curved shape, and the one or more engagement rollers, the central roller, the outer ring and the folded wall portion comprise a slight conical shape in the same direction, so that their surfaces intersect at a single point.

According to a further preferred embodiment, a sealing means is provided which is adapted for optional placement in a first position or in a second position, wherein the sealing means allows in its first position a hooking element to tighten the tube. to achieve a pumping action and, in its second position, prevents a latch from squeezing the tube to allow air or fluid to pass through it.

According to a preferred embodiment, a control means is provided to control the movement of the latch elements to correct the position and speed of the latch elements if necessary. Preferably, the cross section of the tube is elliptical in all four zones, or has a shape similar to an arrangement of two brackets facing each other, such as "()", which results in a reduction in the power required.

Brief description of the drawings

The preferred embodiments of the present invention will now be described with reference to the drawings, in which:

Fig. 1 shows a front perspective view (a) and a rear perspective view (b) of a pump according to a preferred embodiment;

Fig. 2 shows a front perspective view (a) and a rear perspective view (b) of a pump cartridge according to a preferred embodiment;

Fig. 3 shows an exploded perspective view of the pump cartridge of Fig. 2;

Fig. 4 shows a cross-sectional (vertical) view through the pump cartridge of Fig. 2;

Fig. 5 shows a longitudinal (horizontal) section through the pump cartridge of Fig. 2, at the level of a first rolling layer;

Fig. 6 shows a longitudinal (horizontal) section through the pump cartridge of Fig. 2, at the level of a pumping layer;

Fig. 7 shows a longitudinal (horizontal) section through the pump cartridge of Fig. 2, at the level of a second layer of bearing;

Fig. 8 shows a longitudinal (horizontal) section through the pump cartridge of Fig. 2, at the level of a layer of epicyclic gears;

Fig. 9 schematically indicates that the pump cartridge and its interior components comprise a sliding conical shape;

Fig. 10 schematically shows the configuration of the tube and its division into four zones according to a preferred embodiment, illustrating a longitudinal section through the pump cartridge at the level of the pumping layer in (a), a single view of the tube in its curved configuration from above (b), and a single view of the tube in a stretched condition for better understanding (e);

Fig. 11 schematically shows a graph including a curve "a", representing the situation without any correction, and a curve "b" representing a situation without pulses after a correction;

Fig. 12 schematically shows a trumpet curve according to IEC 60601-2-24; and Fig. 13 schematically shows an integrated arrangement comprising a medication reservoir, a pump cartridge and an RFID tag according to a preferred embodiment.

Description of preferred embodiments

In Fig. 1, a pump 2 is shown according to a preferred embodiment. In the embodiment shown, the pump 2 is divided into two parts, that is, a first part 4 that includes a rotary peristaltic pump mechanism, and a second part 6 that only includes a motor to drive the pump mechanism in the first part. 4, and additional hardware such as electronic control and sensing elements (not shown). According to the embodiment shown, the first part 4 defines a consumable pump cartridge 4 which is preferably made of plastic, which results in low manufacturing costs and low weight. The second part 6 defines the remainder of the pump 2 and is called the pump module 6. The pump module 6 comprises on its front part a screen 8 shown in Fig. 1a and keys (not shown), for convenient use and control. As shown in Fig. 1b, the pump cartridge 4 is fixed at the rear of the pump module 6.

In Fig. 2 the pump cartridge 4, which includes the rotary peristaltic pump mechanism, is shown in greater detail. The pump cartridge 4 is provided with a tip 10 defining an inlet port. Tip 10 is provided to preferably position the same in an outlet port of a medication reservoir (not shown) or at a downstream end of an upstream tube (not shown), to create a fluid connection between the reservoir. medication and pump cartridge 4. Additionally, the pump cartridge 4 is provided with an outlet connector 12 that defines an outlet port and is provided to position the same at an upstream end of a downstream tube (not shown). Both of the aforementioned tubes (not shown) are part of an infusion line that runs from the medication reservoir, through the rotary peristaltic pump means in the pump cartridge 4, to a patient. Thus, the fluid flowing along the infusion line enters the rotary peristaltic pump mechanism within the pump cartridge 4, through the tip 10, and exits the same through the outlet connector 12. As can be further seen in Fig. 2, the pump cartridge 4 comprises on one side, which is a front side, a tip air vent 14 and, on the other side, which is the rear side, an element 16 motor coupling to be driven by the motor included in the pump module 6. Likewise, the pump cartridge 4 comprises on its rear side a fixing means 18 by means of which the pump cartridge 4, with its rear side, is fixed to the rear side of the pump module 6 as shown in Fig. 1 By attaching the pump cartridge 4 to the pump module 6, a coupling is created between the motor in the pump module 6 and the motor coupling element 16 on the rear side of the pump cartridge 4, so that the motor of the pump module 6 drive the rotary peristaltic pump mechanism inside the pump cartridge 4.

As illustrated in particular detail in Figs. 3 and 4, the pump cartridge 4 according to a preferred embodiment has two lower and upper parts 20, 21 for press fit of a housing in which all other parts of the mechanism are included, wherein the lower and upper parts 20, 21 define upper and lower casing covers and thus commonly form the casing itself. Three cylindrical rollers 22, 24, 26, each with a gear 220, 240, 260 at the top according to the view of Figures 3 and 4, are used as combined drive and pump elements, and include two planetary rollers 22, 26 of the same diameter and a central or mother roller 24, wherein all cylindrical rollers 22, 24, 26 are arranged in the same (rotating) plane with their axes of rotation oriented side by side in the same plane, and the gear / diameter ratio between the central or mother gear 240 of the central or mother roller 24 and the planetary gears 220, 260 of the planetary rollers 22, 26 determines the reduction ratio of the rotation of the planetary rollers 22, 26 on the rotation of the central or mother roller 24.

In the illustrated embodiment, a gear holder 28 is provided which rotatably supports the planetary rollers 22, 26 and the center roller 24. The gear holder 28 is provided as a rotor and can rotate about an axis of rotation which coincides with the axis of rotation of the central roller 24. As can be seen in Figs. 3 and 4, the upper part of the gear support 28 is provided with a central pin 28a that extends loosely into a recess configured on the inner side of the upper part 20 of the housing, and the opposite lower end or lower part of the central roller 24 is provided with a central cylindrical projection defining the aforementioned motor coupling element 16, as also shown in Fig. 2b, and extends loosely through an opening 21a configured in the bottom of the part. bottom 21 of the Case. Since the center pin 28a is loosely disposed within the recess and the cylindrical motor coupling member 16 is loosely disposed within the opening 21, increased play is created resulting in easy rotational movement of the gear holder 28 and the central roller 24. However, for functional reasons, not such a gear holder 28 is not necessary as the whole pump 2 works fine without it, but the provision of such a gear holder 28 might be advisable for safety reasons, in particular in case the teeth of the gears 220, 240, 260 are damaged or even lost.

Preferably, a small cylindrical magnet may be provided on one of the planetary rollers 22, 26 to define a position of the rollers and to check that the planetary rollers 22, 26 are rotating at a predetermined nominal speed which is measured by a Hall sensor positioned at pump module 6, for safety reasons and motor speed control.

A first outer bearing ring 30 is formed in the lower part 21 of the casing to be disposed within the casing, and a second outer bearing ring 32 is formed in an insert 34 which is disposed within the lower part 21 of the casing. Case. Planetary rollers 22, 26 roll along the interior of the first and second outer bearing rings 30, 32, wherein the first outer bearing ring 30 defines a first bearing stage or layer, as also shown in Fig. 5, and the second outer race ring 32 defines a second race stage or layer, as also shown in Fig. 7. The planetary rollers 22, 26 further extend through a pump stage or layer, shown in Fig. 6, to roll along an elastic tube 36 and squeeze it, said tube being arranged in the pumping layer and housed in a cavity in the lower part 21 of the casing having an "n-shaped cross section. ", as shown in particular in Figs. 3 and 4. Adjacent to the upper part 20 of the housing is a gear stage or layer comprising an outer gear ring 38 which is molded into the lower part 21 of the housing and is shown in Fig. 8, as well as the two planetary gears 220, 260 and the aforementioned planetary or center gear 240 that commonly form an epicyclic gear, as known per se in the prior art, wherein the center gear 240 creates a rotational moment on the planet gears 220, 260 against outer gear ring 38. The two planetary rollers 22, 26 and the central roller 24 are in contact with each other and roll over each other so that the planetary rollers 22, 26 squeeze the elastic tube 36 included in the aforementioned cavity, as shown schematically in Fig. 4. In doing so, the radial forces are compensated and thus eliminated by the bearing in the two layers of roller bearing.

The tangential component of the forces results in a turning moment and hence a torque around the central gear 240 equal to the torque on the central roller 24 and driven through the motor coupling element 16 (see Fig. 2b) by a motor (not shown), included within the pump module 6 (see Fig. 1). Such a torque causes the rollers 22, 24, 26 to rotate to obtain a peristaltic infusion.

As shown in particular in Figs. 3 and 6, the aforementioned cavity in the lower part 21 of the housing forms a cylinder and is bounded by a curved or bent wall portion 40 against which the tube 36 is placed, so that the shape of the tube portion 36 that is in contact with the curved or bent wall portion 40 is determined by the curved or bent shape of the wall portion 40; thus, tube 36 obtains a bent or bent portion as shown in Figs. 3 and 6. As can be seen in Fig. 4, since the aforementioned cavity in the lower part 21 of the casing has an "n" -shaped cross section, it is limited by the two bearing rings 30, 32 and the portion 40 wall. As can be further seen in Figs. 3 and 4, the radial depth of the cavity is less than the thickness of the tube 36 in its uncompressed state.

Tube 36 is attached to curved or bent wall portion 40 of housing bottom 21 both tangentially and radially, by means of hooks 42 arranged along the periphery of tube 36 and inserted into corresponding recesses 44 located in the wall portion 40, as shown in particular in Figs. 3 and 6. Thus, it is not possible that during the rolling movement of the planetary rollers 22, 26 the tube 36 suffers jerks and extensions.

As further shown in Figure 3, a part of the curved wall portion 40 located in the lower part 21 of the housing is interrupted by a recess in which a shutter 46 is housed. The shutter 46 is movable between a first position, or closed position, and a second position or open position. In its first position or closed position, the plug 46 forms a continuous part of the curved wall portion 40 where the tube 36 is housed, so that the planetary rollers 22, 26 can squeeze the tube 36. In its second position o In the open position, the shutter 46 is arranged such that the tube 36 cannot be squeezed in the region thereof, but rather that the tube 36 can be relaxed and free of tension so that, in particular for sterilization purposes, air or fluid can pass freely through of the tube 36 when the pump 2 is not operating, nor therefore the rotary peristaltic pump mechanism within the pump cartridge 4, and a planetary roller 22 or 26 is located in the area of the obturator 46. The obturator 46 is configured and arranged so that by a pressing action it is moved to its first position, or closed position, when the pump cartridge 4 is attached to the pump module 6 (see Fig. 1). Additionally, the shutter 46 is configured and arranged so that it remains in its first position or closed position when the pump cartridge 4 is released from the pump module 6, to prevent free flow.

Thus, the rotary peristaltic pumping mechanism according to the illustrated preferred embodiment has four operating stages or layers along its height. A preferred implementation, as shown, features a first operating layer defining a first bearing layer that includes a first roller bearing arrangement provided by the planetary rollers 22, 26, the center or mother roller 24 and the first ring 30 of outer bearing, a second layer that is a pumping layer that includes a rotating peristaltic pump means provided by the planetary rollers 22, 26, the central or mother roller 24, the tube 36 and the wall portion 40, a third layer that defines a second bearing layer that includes a second roller bearing arrangement provided by the planetary rollers 22, 26, the central or mother roller 24 and the second outer bearing ring 32, and finally a fourth layer that defines a gear layer epicyclics provided by planetary gears 220, 260, center gear 240, and outer gear ring 38. Due to this arrangement, an appropriate distribution of forces is achieved in the bearings, where the cavity of the lower part 21 of the casing that houses the tube 36 comprises the aforementioned "n" -shaped cross section, its height being limited by the outer bearing rings 30, 32 of the bearing layers and their radial width being limited by the curved wall portion 40, for a complete tightening of the tube 36, as shown in Fig. 4, at a maximum pressure as shown require the pump.

Fig. 5 shows the first rolling layer comprising the central cylindrical or driving mother roller 24 and the planetary rollers 22, 26 that are in contact with the central or mother roller 24, and the first outer bearing ring 30 that forms a 360 ° crown, which ensures that, as in all bearings, when tightening the tube 36 the opposing forces acting against the planetary rollers 22, 26 cause a forced reaction in the bearing parts of the three rollers 22, 24 , 26 online, and therefore they are offset and eliminated from each other. Thus, there is no friction in the axes of rotation (not shown) of the rollers 22, 24, 26 as they are not subjected to any radial force, which results in a reduction in battery consumption compared to the technique previous. Due to the compensation of the counter forces, omitting the center pin 28a at the top of the gear holder 28 could alternatively be considered.

Fig. 6 shows a second layer that defines the layer of the pump that does not comprise a body or cylinder closed at 360 °, as in the remaining layers, but is open at approximately 170 °, where each planetary roller 22, 26 it functions as a rotary peristaltic pump roller that presses the elastic tube 36 against the outer wall portion 40 of the lower part 21 of the housing, as shown in Fig. 4.

Fig. 7 shows a second bearing layer comprising the central cylindrical or driving mother roller 24 and the planetary rollers 22, 26 that are in contact with the central or mother roller 24, and the second outer bearing ring 32 a crown 360 °, which ensures that, as in all bearings, when tightening the tube 36 the opposing forces acting against the planetary rollers 22, 26 cause a forced reaction in the bearing parts of the three rollers 22, 24, 26 online, and thus offset and eliminate each other. Thus, there is no friction on the axes of rotation (not shown) of the three rollers 22, 24, 26, since they are not subjected to any radial force.

Finally, Fig. 8 shows the gear layer comprising the outer gear ring 38 that specifies the position of the planetary gears 220, 260 in relation to the rotation of the central or mother gear 240, which rotates through coupling with a motor (not shown) in pump module 6. The position of the center or mother gear 240 is stable in the center of the outer gear ring 38. The nominal distance of the gear teeth for good operation and lower friction of the gear ring is determined by the first and second bearing layers, which are shown in Figs. 5 and 7, where the rollers 22, 24, 26 determine the exact distance of the respective teeth.

As can be seen from the above description, the planetary roller 22 and the planet gear 220 commonly form a first integral rotating body, the central or mother roller 24 and the planet gear 240 commonly form a second integral rotating body, and the planetary roller 26 and planet gear 260 commonly form a third integral rotary body. These integral rotating bodies, wall portions of the lower and upper parts 20, 21 of the housing and other components comprise a slightly conical shape in the same direction, to achieve a structure whose cross-section is slightly V-shaped, where the angle of the "V" defines a traction angle necessary to unmold said components in the case of plastic production. The aforementioned slightly conical or V-shaped structure can be sensed in Fig. 4, but it has been exaggerated in Fig. 9 for better illustration.

Namely, rollers 22, 24, 26 cannot be injection molded if they are to be completely cylindrical in shape. Although they do not present a parting line on the sides, it is necessary that they have a traction angle of certain degrees in the face of the draft, which results in the negative effect that if the casing or body are cylindrical and the rollers are slightly taper, there will be a clearance or tolerance in one of the two rolling stages that will not be acceptable. Therefore, to solve the above-mentioned injection molding problem, the aforementioned construction has a slightly V-shaped conical shape, taking into account the design rule that the conical shapes on all rollers and on the casing or cylinder carry a perfect rolling motion over each other under the condition that all tapered lines intersect at a single point, as shown schematically in Fig. 9b. Thus, the casing or cylinder, the mother or central roller 24 and the planetary rollers 22, 26 have a slightly conical shape so that their lateral lines intersect at a point remote from the pump cartridge 4 since the angle of pull is relatively small, as is evident from Fig. 9a. While the planetary rollers 22, 26 and their associated gears 220, 260 are inclined, the main or center gear 240 is cylindrical so that the planetary rollers 22, 26 and the center or mother gear 24 roll and mesh with each other. The inner walls of the casing or cylinder are also slightly inclined to match the surface of the rollers 22, 24, 26, which is also applicable to the two outer bearing rings 30, 32 that make contact with the rollers 22, 26 to allow rolling action.

Its elastic tube 36 is preferably made of injection molded rubber or silicone, resulting in a production tolerance of only up to 1%, which is a requirement for replacing syringe pumps that have a precision tolerance of total flow of approximately 2%. Also preferably, the elastic tube 36 does not have a round cross section in its relaxed state, but rather has what is called an elliptical or angled up and down cross section with a shape similar to the arrangement of two brackets facing each other. , that is "()", which results in a drastic reduction in the energy required and, therefore, in the capacity and size of the battery.

Since the elastic tube 36 is injection molded, preferably made of injection molded silicon and with a cross section that, as mentioned above, can have different sizes and cross sections in order to nullify a pulsed infusion, to reduce the index of constancy and the necessary power, and to achieve a better detection of the pressure and a watertight fixation of the ribbed connector at the inlet 50 and the outlet 52 of the tube 36. This is possible because the demoulding process is carried out by blowing the tube on an insert pin. Additionally, a particular type of material can be selected and the tube surface can be treated to reduce rolling friction.

In accordance with the present invention, the tube 36 is divided into four sections or zones of rotation that are defined as the first to fourth zones A to D, which are directly joined to each other from the inlet 50 to the outlet 52 in the water orientation. down defined by the direction of flow of a fluid and represented by arrow A, as shown in Fig. 10.

The first zone A which is located downstream adjacent to the inlet 50 and which defines the most upstream zone is provided such that a planetary roller 22 or 26 engages the tube 36 during movement along the first zone A. The first zone A extends over an angular distance (defining its length) by a few degrees, preferably 5 ° to 15 °, and is provided as a pressure management or safety stage. Upon engagement with the tube 36, the planetary roller 22 or 26 begins to squeeze the tube 36 so that fluid is encapsulated within the tube 36 between said planetary roller and a precursor or leading planetary roller. The first zone A guarantees safety thanks to the relay between one of the planetary rollers (eg 22) and the next planetary roller (eg 26), where there is no free flow due to the fact that at the Minus one planetary roller 22, 26 is squeezing the tube 36 at all times, even if the planetary roller 22 or 26 has lost perfect clearance during manufacturing. Furthermore, in the first zone A, which defines the initial section or stage of rotation, the cross section of the tube 36 increases so that the pressure builds up as represented in the aforementioned equation

V AV2 / A9 - AV1 / A9 = V Vdifference

to equalize the pressure at the outlet 52 of the tube 36 to the desired infusion pressure and avoid hydraulic shock upon disengagement of a planetary roller 22 or 26 from the tube 36. This is useful for subcutaneous infusions having elevated downstream pressure. Since no pressure build-up is required for intravenous infusion, tube 36 located within first zone A has a nominal or standard cross-section.

Due to the desire to achieve a constant infusion, a constant infusion fluid flow (volume displacement AV) per unit time (At) along the rolling path of the planetary rollers 22, 26 and hence is desirable. Thus, along the entire length of the tube 36, when the planetary rollers 22, 26 roll with a constant rotational speed w = 2n / t along the tube 36. To achieve this, the volume AV created by the displacement action of The volume of the planetary rollers 22, 26 must be constant along the rolling path of the planetary rollers 22, 26, due to the following equation:

Flow = AV / At = (AV / A9) • (A9 / At) = (AV / A9) • C,

where C = A9 / At = w is a constant that represents a constant rotational speed of the planetary rollers 22, 26 in angular units per unit of time.

Therefore, the volume displacement action per degrees of rotation of a planetary roller 22, 26 should be constant at any point in the infusion cycle, where in an embodiment with two planetary rollers according to the present embodiment, as described and illustrated herein, there are two cycles per revolution. The second through fourth zones B through D, as described below, ensure that these needs are met.

The second zone B, which follows the first zone A in a downstream direction, begins at a starting point where a planetary roller 22 or 26 enters the second zone B at the same time that the forward planetary roller stops squeezing the tube 36 and is to be disengaged from tube 36, so that a communication flow occurs. At that moment, the follower or rear planetary roller simply enters the second zone B and takes over in the infusion. The tube 36 has in the second zone B a higher cross section than normal, and in particular in the third and fourth zones C and D. The cross section of the second zone B increases by an amount that leads to an increase in volume that is at least equal to an increase in volume AVd / A9 in the fourth zone D, as a result of the forward planetary roller disengaging from the tube 36. In other words, the increase in volume due to a larger cross section within the Zone B is at least equal to a vacuum caused by the disengagement or release of the precursor or leading planetary roller with respect to the tube 36 when it travels along the fourth zone D. Thus, said vacuum is compensated and a fluid flow balance. The third zone C, which continues downstream of the second zone B, begins at a starting point where the follower or trailing planetary roller enters the third zone C, while the leading or precursor planetary roller has already disengaged from the tube. 36 and therefore no longer contacts the tube 36. Preferably, the third zone C comprises a normal or nominal cross section that is dimensioned so that a linear flow of the fluid is achieved through the third zone C, to infuse at a standard AV / A9 rate. According to the embodiment illustrated in figure 10, the sum of the angular distance of the second zone B and the angular distance of the third zone C is 180 ° in total for the embodiment that has two planetary rollers 22, 26 that they are arranged diametrically opposite the central or mother roll 24, as previously described with reference to Figs. 3 to 8. In the case of an alternative embodiment (not shown) that has three planetary rollers that are separated from the central or mother roller by the same radial distance, where two adjoining planetary rollers are separated from each other by an angular distance of 120 °, the sum of the angular distance of the second zone B and the angular distance of the third zone C is 120 ° in total.

The fourth and last zone D, which continues downstream of the third zone C and which is the most downstream zone, is adapted so that the planetary rollers 22, 26 disengage from the tube 36 during movement along the fourth zone D. Namely, the fourth zone D is provided for a controlled release of the precursor or leading planetary roll from the tube 36, wherein, according to the illustrated embodiment, a controlled release is achieved due to an increase in the radius of curvature. , r Ar / A9. In particular, the increase in radius can follow an asymptotic line or a portion of a spiral. This controlled curvature defines a release arc that depends on the ability to increase the cross section of the tube 36 in the second zone B, and which cannot be minimal since then a large bubble would be needed in the second zone B, which makes it difficult the production.

The volume vacuum created by the disengagement or release of a planetary roller 22 or 26 with respect to the tube 36 serves to determine or calculate the volume of the second zone B having an increased cross section of the tube 36. In other words, a From the AVd / A9 view, it is calculated that the increase in volume in the second zone B is equal to the volume void additionally created in the fourth zone D due to the disengagement or release of the planetary roller with respect to the tube 36. Thus, the The volume void created by A9 according to -Vd / A9 within the fourth zone D is equally compensated by a presumed overinfusion caused by a larger cross-section of the tube within the second zone B, according to AVb / A9, with AVb / A9 = AVd / A9 and therefore

(AV / A9 AVb / A9) - (AVd / A9) = AV / A9

which results in a constant flow in any angular position 9 due to a balance of the fluid flow, so that for each point in the fourth zone D there is a hanging point of compensation in the second zone B.

Thus, there is a correlation of the curvature of the tube 36 with the increase in the cross-section of an upstream portion of the tube 36 corresponding to the second zone B, such that the additional volume of the tube 36 created by the disengagement or release of the planetary roll relative to tube 36 within fourth zone D is offset by the additional volume provided by a larger cross section of tube 36 along second zone B. According to the embodiment as illustrated in figure 10 , the sum of the angular distance of the third zone C and the angular distance of the fourth zone D is 180 ° in total for the embodiment that has two planetary rollers 22, 26 that are arranged diametrically opposite to the central or mother roller 24 , as described above with reference to Figures 3 to 8. In the case of an alternative embodiment (not shown) that has three planetary rollers that are separated from the center roller to the mother by the same radial distance, where two adjoining planetary rollers are separated from each other by an angular distance of 120 °, the sum of the angular distance of the third zone C and the angular distance of the fourth zone D is 120 ° total.

Therefore, the increase in volume per angle of rotation is given by the rear planetary roller that is travels along the second zone B once a release or disengagement of the forward planetary roller has begun with respect to the tube 36 in the fourth zone D. As a result, the rear planetary roller supports the required flow of fluid.

Thus, the flow (AV / A9) • u> compared to a planetary roller 22 or 26 in case only one planetary roller engages the tube 36 in the third zone C should be equal and constant to the flow (AV2 / A9 AV1 / A9) • w in case of engagement of two planetary rollers 22, 26 in the second zone B and the fourth zone D, respectively. Since (AV1 / A9), caused by the leading or leading planetary roller (eg 22) becomes negative due to the suction in the fourth zone D, AV2 / A9, created by the following or trailing planetary roller (e.g. 26) that travels along the second zone B, it will need to be positive to balance the sum of AV1 / A9 and AV2 / A9 to be equal to AV / A9 within the third zone C, along which only one planetary roller 22 or 26 is moving at a time. Consequently, as already described above, if the cross section of the tube 36 within the fourth zone D is equal to the cross section of the tube 36 within the third zone C, the cross section of the tube 36 within the second zone B must be larger to compensate for the loss. Commercially available numerical flow emulators known in the prior art can be used to calculate vacuum and compensation. If the planetary rollers do not have a minimum diameter, resulting in a late decompression and opening of the tube 36 within the fourth zone D, a suction may be felt from the outlet 52 prior to opening when it is to be disengaged or released from the tube. 36 the front planetary roller, as long as a flow from behind is not yet possible. This can be corrected by allowing a rapid opening of the flow without disturbing the controlled disengagement or release of the planetary roller within the fourth zone D, which can be accomplished by providing a sump (not shown) within the elastic tube that begins at the start of the flow. fourth zone D, to suddenly open the flow supported by the rear planetary roller. With a sudden opening of the flow, instead of a sump within the tube, it is also possible to provide with the same effect a step 48 of partial or full width as further shown in Fig. 3, wherein the cross-section in the form of "n" of the aforementioned cavity of the lower part 21 of the casing is deepened in the radial direction within the fourth zone D, to effect a pronounced setback of the wall portion 40 for the necessary depth to open only the flow from behind the tube 36, where the remainder of the fourth zone D is provided for a controlled disengagement of the planetary rollers from the tube 36 in association with the increased volume of the second zone B, as described above .

The angular distance (defining the length) of the second zone B is preferably equal to the angular distance of the fourth zone D and may preferably be from 20 ° to 60 ° for a realistic controlled release or disengagement of the forward planetary roller from the tube 36 , within the fourth zone D, without any disturbance of the flow. An increase in angular distance would result in a smaller area increase per degree, and a decrease in angular distance would result in a smaller mechanism. Thus, the construction depends on the specifications of use, where all the possibilities from a few degrees to 180 ° can offer a constant flow. The sum of the angular distances of the four sections A to D must be equal to or less than 360 °.

Whereas the first zone A is provided for the planetary rollers 22, 26 to engage with the tube 36 during movement along the first zone A, and the fourth zone D is provided for the planetary rollers 22, 26 to disengage of tube 36 during movement along fourth zone D, second and third zones B and C are provided so that at least planetary roller 22 or 26 remains engaged with tube 36 during movement along second and third zones B and C.

The following describes how the aforementioned construction works according to a preferred embodiment of the present invention:

At the same time that a leading or leading planetary roller at the end of fourth zone D is disengaged or released from tube 36, a trailing or follower planetary roller (e.g. 22) is about to enter third zone C so that this last planetary roller takes over as a new precursor or leading planetary roller, which at that time will be the only planetary roller that is in contact with the tube 36, and therefore squeezing the same while moving along of the third zone C. Thus, a constant AV / A9 infusion is provided. Before this last mentioned planetary roller, which is now the forward planetary roller, reaches the terminal portion of the third zone C, the next upstream planetary roller (e.g. 26) will enter the first zone A and into contact with the tube 36, squeezing it, so that between these two adjoining planetary rollers 22, 26 a standard or nominal volume is encapsulated within the tube 36. The encapsulation of a volume with the same repeatable quantity ensures the desired precision in the infusion. This is ensured by fixing the tube 36 to the wall portion 40 due to the cooperation between the hooks 42 on the tube 36 and the corresponding recesses 44 in the wall portion 40.

Preferably, the cross section of the tube 36 in the first zone A may be greater than the cross section of the third zone C, where in particular the cross section of the tube 36 in the first zone A decreases from a high amount, at the beginning of the first zone A, up to a normal or nominal amount at the end of the first zone A corresponding to the normal or nominal amount of the cross section of the tube 36 in the third zone C. Thus, within the first zone A a increased infusion pressure that is higher than the pressure within the infusion line corresponding to atmospheric pressure, resulting in that within the first zone A tube 36 inflates due to

V AV2 / A9- AV1 / A9 = V Vdifference.

This increase in infusion pressure may be less or zero for intravenous infusions and greater for subcutaneous infusions. As a result, after unhooking or releasing the forward planetary roller from tube 36 within the fourth zone D, the pressure at that point will be able to equal the downstream pressure and thus the fluid flow out of the volume. encapsulation will be essentially uniform. Thus, there will be no backflow of fluid into the elastic tube 36 since the pressures in front of and behind said planetary roller will be essentially the same.

As already mentioned above, in the described embodiment that has two planetary rollers 22, 26, at the same time as the rear planetary roller located upstream exits the first zone A and enters the second zone B, the precursor planetary roller or striker leaves the third zone C and enters the fourth zone D and, therefore, begins to loosen or disengage from the tube 36. Due to the release or disengagement with respect to the tube 36, a communication is generated that opens under the roller forward planetary, resulting in immediate release of the optional high fluid pressure created in the first zone A. This involves balancing the pressures so that there is no pressure and flow disturbance, which would otherwise result from the fact that a higher infusion pressure could cause the fluid to flow back and inflate the elastic tube and create a momentary negative impulse of the flow.

During simultaneous movement along the second and fourth zones B and D, each partial release of the leading or precursor planetary roller within the fourth zone D creates a vacuum, and each partial rotation of the upstream rear planetary roller within the second Zone B creates an over-infusion, which, however, are essentially balanced with each other so that the infusion will remain essentially constant due to compensation for flow differences due to the special configuration of the second zone B, as explained previously.

Fig. 11 shows the effect of the pulseless correction described above as a graph of weight versus the angle of rotation of the planetary rollers 22, 26, over the entire angular range from 0 ° to 360 °, where the curve "a" represents the situation before correction and shows a pulse for each of the two rotational infusion cycles, at the two roller exchange points, when both planetary rollers are still simultaneously engaged with the tube 36, and the Curve "b" shows a pulseless situation after correction due to measurements as described above and thus defines an essentially straight line.

Fig. 12 shows a trumpet curve with the aforementioned flow linearity corrections, but without using any additional electronic means of correction, so as to match the best syringe pumps, where the constancy index as defined above it is less than 2 min to accommodate current short-duration drug infusion needs. The trumpet curve is a well known graph in the infusion field and is based on a statistical measurement where, for more details, reference is made to the International Standard IEC 60601-2-24.

It is known in the art that flow correction can also be accomplished by temporarily accelerating the motor speed at so-called infusion (pulse) rotational angles. Namely, as shown from the above-mentioned equation flow rate = (AV / A9) • (A9 / At), a decrease in AV by a predetermined angle 9 can be compensated by an increase in A9 / At. However, this solution was not commercially successful in the 1990s as patients complained that such a pump would be unsuitable as irregular flow was erroneously perceived due to an alleged irregular motor sound. If a slight acceleration and deceleration of the motor is carried out after a mechanical flow correction, as described above, it will not be possible to perceive it, so that in such a case marketing will no longer be a problem.

In accordance with the present invention, a rotary peristaltic pump mechanism is provided with an increased volume section of tube 36 within second zone B and, later on, a sudden increase in depth due to step 48 within the opening of the fourth zone D for flux correction, preferably associated with different (not equal) timing settings per step of the motor at low speeds. Such a step is defined as what is known as a motor positioning feedback step where, in a preferred embodiment, there are approximately 80 steps per half rotation corresponding to a 180 ° roller relay section, where an infusion rate determines a normally constant interruption time per step. If the aforementioned mechanical correction is not perfect, from a measured volume to a step graph, it should be noted that the portions of the curve that are above a velocity line represent an infusion requiring less timing interruption, and the portions that are below the velocity line represent an infusion that requires less timing interruption, where an electronic correction look-up table per infusion step is defined and determines the time of each step to fully correct for flow linearity . With such small differences in timing, users no longer perceive an additional electronic correction.

The constancy index is drastically reduced due to the aforementioned linearity in the infusion and, in combination with a tube manufactured by injection molding, a production tolerance (precision) of maximum 2% can be achieved, which makes a peristaltic pump is as suitable as a syringe pump, in particular for biological drugs, insulin infusion, as well as catecholamines, heparin and nitrates that require short-term precision with a low constancy index and high precision. In particular for biologics and insulin, the pump mechanism can be provided with a cylinder whose diameter is only 10 mm, allowing extremely small size in combination with multi-layer reservoirs (e.g. for oxygen barriers and CO2) (that is, they comprise a polypropylene material with a low temperature on the outside and a high temperature on the inside and include a binder material such as TPE, or other barrier materials such as polytetrafluoroethylene (TPFE) or polyvinylidene chloride ( PVDC) or ethylene vinyl alcohol (EVOH), as known eg from 9,162,025 B2) in which a pre-filled medicine can be stored for many years. Thus, it is possible to provide a pump whose overall size is 6.45 cm2 (1 square inch). Therefore, the present technology can be used for high volume bolus injectors. For biological fluids and insulin, low volumes and generally ultra-low speeds are required so that a complete patch pump can be provided with the aforementioned pump consumable cartridge 4 as the infusion set (further comprising a needle infusion needle). Teflon (PTFE), as known in the prior art) without a conventional motor, but a directly connected drive sawtooth gear in combination with the central or mother roller 24, 240, wherein said drive gear rotates tooth tooth through a ratchet that advances the rotation but blocks a counter rotation due to the force of a spring, loaded for expansion, said spring being able to comprise a heat-shrinkable element made of a shape memory alloy, such as a steel wire. nitinol which is known from US 6656159 B2. Such shape memory wire is contracted by electrical energy and displaces a gear tooth, resulting in a few angles of rotation of the center or mother roll and when the electrical power is cut, it is expanded by spring force to a holding position to engage the next tooth.

For parenteral nutrition, a pre-filled reservoir known in the art includes three or more compartments that are pre-filled with nutrients that can be mixed by hand to break the seal between the compartments prior to use. To avoid contamination more effectively, self-administration of content by untrained patients is possible as follows:

The pre-filled reservoir comprises three or more pre-filled compartments that include sealing strips therebetween, which can be opened by hand to mix the contents. The pump cartridge can be fluidly connected to the reservoir through a three-way inlet valve, to avoid the risk of contamination upstream of a prior art tip type connection. Furthermore, at the distal end of the downstream tube an anti-pollution Luer connector is provided (as disclosed in EP 2756863 A1 or US 2014/0207118 A1), where at first a gravity priming occurs after opening said valve manually, where the flow is stopped at a hydrophobic membrane of the connector, and then the user removes a plug from his central venous catheter and said connector assembly and discards both plugs connected to each other, and then makes the required connection without touching part any of the catheter other than the rear of the connector and without any risk of contamination at both ends of the infusion line. A pump drive controller is then coupled to the infusion set. The container comprises, in particular on one of its edges, an RFID tag in which the nutritional content is stored. The nutritional content and its volume are recorded by the pump and sent wirelessly to a distant server, where they are stored in a database and sent to medical personnel in view of the dates for a nutritional review. Additionally, the pre-filled tank can be provided with internal micro-grooves that do not allow self-sealing of the plastic sides by suction, so that said tank can be used even in a horizontal position or on an outpatient basis without the risk of generating upstream occlusion alarms.

By way of example, Fig. 13 shows a pre-filled medication reservoir 60 that includes three compartments or chambers 62. As will be seen later in Fig. 13, an RFID tag 64 is located in the lower edge area 60a of the medication tank 60. Preferably, the label 64 may be welded to the material of the medication reservoir 60 between the upper and lower sheets. In the embodiment illustrated according to Fig. 13, a pump cartridge 4 is also disposed in the lower edge portion 60a of the medication reservoir 60. In contrast to what is shown in Figs. 1-3, a tip is not present as the inlet of the rotary peristaltic pump mechanism of the pump cartridge 4 is in direct fluid communication with the medication reservoir 60. An antenna 66 to which the tag 64 is coupled is provided, in the form of a wire pattern surrounding the pump cartridge 4 so as to ensure that a tag reader, included in a pump module 6 or a pump controller pump, you can always read the contents of the label which, by the way, is also printed on the medication reservoir 60. Also, Fig. 13 shows a downstream tube 68 that is coupled to the outlet of the rotary peristaltic pump mechanism within the pump cartridge 4 and that extends to an anti-pollution luer connector (not shown), attached to the catheter connector. of a patient (not shown).

Claims (15)

1. An infusion pump device, comprising peristaltic pump means including - a flexible, preferably elastic stationary tube (36) having an inlet (50) and an outlet (52) and is provided to accommodate a fluid flowing in a downstream direction from the inlet (50) to the outlet (52) , and - at least two engagement elements (22, 26) which are spaced from each other by a constant predetermined distance and which are provided to engage locally with the tube (36) and to be repeatedly displaced along the tube (36 ), in the downstream direction, to locally squeeze the tube (36) and achieve a pumping action during the movement of the latch along the tube (36) and to encapsulate a volume of the tube (36) between two elements ( 22, 26) of adjoining hitch, - wherein the tube (36) comprises first to fourth zones (A to D) that are directly connected to each other in a downstream direction, - wherein the first zone (A), which is the most upstream zone, is provided so that a hooking element (22, 26) can engage with the tube (36) during movement along the first zone (A), - wherein the second and third zones (B, C) are provided so that an engagement element (22, 26) remains engaged with the tube (36) during movement along the second and third zones (B, C), - wherein the fourth zone (D), which is the most downstream zone, is provided so that a hooking element (22, 26) can be disengaged from the tube (36) during movement to along the fourth zone (D), - where the length of each of the first, second and fourth zones (A, B and D) is shorter than the distance between the two adjoining coupling elements (22, 26), and - where the cross section of the second zone (B) is greater than the cross section of the third zone (C) by an amount that leads to an increase in volume that is at least equal to an increase in volume displaced in the fourth zone (D), as a result of unhooking a hooking element (22, 26) from the tube (36), characterized by what - the second zone (B), which follows the first zone (A) in a downstream direction, begins at a starting point where a coupling element (22) enters the second zone at the same time as an element (26) adjoining front hitch located in the fourth zone (D) simply stops tightening the tube (36), and it will unhook it from the tube (36) so that a flow communication arises, - the third zone (C), which follows the second zone (B) in a downstream direction, begins at a starting point where a coupling element (22) enters the third zone (C) at the same time that it is already has disengaged an adjoining front hitch element (26) from the tube (36) and therefore no longer makes contact with the tube (36), - the length of the third zone (C) is also shorter than the distance between the two neighboring coupling elements (22, 26), - the sum of the distances of the second and third zones (B, C) is equal to the distance between the two neighboring coupling elements (22, 26), and - the length of the second zone (B) is equal to the length of the fourth zone (D). The device according to claim 1, wherein the length of the third zone (C) is greater than the length of the first zone (A) and / or of the second zone (B) and / or of the fourth zone (D). The device according to claim 1 or 2, wherein the cross section of the first zone (A) is larger than the cross section of the third zone (C). The device according to at least any one of the preceding claims, further comprising a casing (20, 21) housing the peristaltic pump means and fixing means (42, 44) for fixing the tube (36) to the casing (20, 21), to prevent movement of the tube (36) with respect to the casing (20, 21). The device according to at least any one of the preceding claims, - wherein the peristaltic pump means is a rotary peristaltic pump means comprising a rotor (28) that is provided with the engagement elements (22, 26), wherein the tube (36) comprises a bent portion essentially having a partial cycle form, and - where the length of the zones (A to D) is represented by an angular distance. The device according to claim 5, wherein the angular distance of the first zone (A) is up to 15 °. The device according to claim 5 or 6, wherein the angular distance of the second zone (B) is from 20 ° to 60 °. The device according to at least any one of claims 5 to 7, comprising two engagement elements (22, 26) that are arranged essentially diametrically opposite to a rotational axis of the rotor, wherein the sum of the distances angular of the second and third zones (B, C) is equal to 180 °. The device according to at least any one of claims 5 to 7, comprising three engagement elements (22, 26) that are separated from a rotation axis of the rotor (28) by the same radial distance, wherein two adjoining hooking elements (22, 26) are separated from each other by an angular distance of 120 °, where the sum of the angular distances of the second and third zones (B, C) is equal to 120 °. The device according to at least any one of claims 5 to 9, wherein the latch elements (22, 26) are provided as latch rollers. The device according to claim 10, wherein the rotor (28) comprises a central roller (24) which frictionally engages with the engagement rollers (22, 26). The device according to claim 11, further comprising a housing (20, 21) including a folded wall portion (40) that supports at least a portion of the tube (36) and provides the tube (36) with a curved shape, wherein in the fourth zone (D) the folded wall portion (40) is provided with a step (48) in a radial direction to make a pronounced setback of the folded wall portion (40) to the depth necessary to open the flow from behind the tube (36). The device according to claim 11, further comprising a housing (20, 21) including a folded wall portion (40) that supports at least a portion of the tube (36) and provides the tube (36) with a curved shape, wherein the one or more engagement rollers (20, 26), the center roller (24), the outer ring (30, 32) and the folded wall portion (40) comprise a slight conical shape therein direction so that their surfaces intersect at a single point. The device according to at least any one of the preceding claims, further comprising a shutter means (46) which is adapted for optional placement in a first position or a second position, wherein the shutter means (46) allows in its first position that a latch element (22, 26) squeezes the tube (26) for a pumping action, and in its second position it prevents a latch member (22, 26) from squeezes the tube (26) to letting air or fluid pass through tube (26). The device according to at least any one of the preceding claims, further comprising control means for controlling the movement of the hooking elements (22, 26) to correct the position and speed of the elements (22, 26 ) of hitch if necessary.